Sound Metric Balance of Engine Cooling Fan Noise to enable Delivery of Good Exterior Sound Quality Bentley Motors Limited, Crewe, England

Format:

Conference/Event

Author/Creator:

Senapati, Senapati, author.

Contributor:

Evans, Graham

Hankinson, Aaron

Conference Name:

SAE 2011 Noise and Vibration Conference and Exhibition (2011-05-16 : Grand Rapids, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2011

Summary:

The drive for lower CO₂ emissions places ever greater demand oncooling dissipation for a multi-cylinder internal combustionengine. This challenge has increased the requirements of the enginecooling system, particularly in countries where high ambienttemperatures prevail and HVAC usage is high. Environmentalnecessity coupled with market demands have resulted in cars whichemit a higher level of cooling fan noise which is intrusive in anurban environment and objectionable to customers.Conventional quantification of noise using traditional units andmetrics was found to be insufficient for effective Sound Qualityanalysis. To assist Bentley Motors, a high performance luxuryvehicle manufacturer, with its brand cachet and its commitment tothe environment and customer, a new sound metric analysis has beendevised to help the business deliver an ever-quieter exterior powerunit cooling system.A rig simulating a vehicle cooling fan installation has beenconstructed to compare Bentley fans with competitor fans. Rankingthe fans in terms of overall sound pressure level for a given fanspeed was found to correlate poorly with the subjectively perceived"best" fan. Sound metrics were used to characterize thefans, with "sharpness" displaying good correlation withsubjective perception of tonality and "loudness"correlating well with flow noise. Furthermore, it was found that alinear balance between sharpness and loudness with increased speedled to improved perception throughout the speed range. Areas ofpoor balance were subjectively found to be speeds where eithertonality or flow noise dominates human perception. Acoustic targetsin terms of balance between sharpness and loudness were establishedfor Bentley fans

Notes:

Vendor supplied data

Publisher Number:

2011-01-1530

Access Restriction:

Restricted for use by site license